1. Field of the Invention
The present invention relates to photographic apparatus and, in particular, to an improved mechanism for insuring movement of a piezoelectric firing spring to a latched position in such apparatus.
2. Description of the Prior Art
It is known in the photographic arts to provide for the ignition of a flashlamp by means of an electric pulse generated by a piezoelectric crystal and to provide for the synchronization of such flash ignition with shutter operation of a camera. See U.S. Pat. Nos. 2,856,564; 2,972,937 and 3,106,080. More recently, apparatus has been developed in which a plurality of flashlamps, fireable by electric energy generated by a piezoelectric crystal, are assembled into a multilamp array. In one such array, as is disclosed more fully in the referenced, co-pending U.S. application Ser. No. 528,529, entitled CAMERA FLASH SOCKET, all of the lamps are aligned in the same direction and each lamp has its own reflector, with a switching mechanism internal to the array for firing a particular lamp.
As the piezoelectric crystal is to be struck repeatedly, it becomes necessary and desirable to provide mechanisms for striking the crystal within the camera so that a multitude of electric pulses of substantially the same magnitude and duration may be produced and for coordinating such mechanisms with other camera functions. One such mechanism is disclosed in the referenced, co-pending U.S. application Ser. No. 528,305, entitled FILM ADVANCE-FLASH INTERLOCK MECHANISM. In that mechanism, a single latch member is utilized to maintain a piezoelectric firing spring in its latched position prior to actuation of the camera's shutter drive mechanism and to prevent short-stroke operation of the film advance mechanism prior to return of the piezoelectric firing spring to its latched position. While effective, this mechanism depends upon proper positioning of the latch member to prevent short stroke operation and thus requires a relatively heavy latch member to minimize unwanted movements during camera operation. Such a construction increases the force required to be exerted by the shutter drive mechanism in order to properly release the latch mechanism for flash synchronization, an increase which is undesirable in combination with other forces present in the camera.